Wireless power transmitters and associated base stations for transmitting power at extended separation distances

ABSTRACT

A power transmitter includes a control and communications unit and an inverter circuit configured to receive input power and convert the input power to a power signal. The power transmitter further includes a coil configured to transmit the power signal to a power receiver, the coil formed of wound Litz wire and including a first coil portion and a second coil portion, the first coil portion defining a top face and a first diameter, the second coil portion defining a second diameter, the second diameter being greater than the first diameter. The power transmitter further includes a shielding comprising a ferrite core and defining a cavity and a magnetic ring, the cavity configured such that the ferrite core substantially surrounds all but the top face of the first coil portion and the second coil portion is positioned, at least in part, above the magnetic ring.

TECHNICAL FIELD

The present disclosure generally relates to systems and methods forwireless transfer of electrical power and, more particularly, towireless power transmitters for transmitting power at extendedseparation distances.

BACKGROUND

Wireless power transfer systems are used in a variety of applicationsfor the wireless transfer of electrical energy, electrical powersignals, electromagnetic energy, electrical data signals, among otherknown wirelessly transmittable signals. Such systems often use inductivewireless power transfer, which occurs when magnetic fields created by atransmitting element induce an electric field, and hence, an electriccurrent, in a receiving element. These transmission and receiverelements will often take the form of coiled wires and/or antennas.

Because some wireless power transfer systems are operable and/or mostefficient in the near-field, some transmitters may be limited to havingoperability only at restrictively small gaps between the transmittercoil and the receiver coil. To that end, typical wireless powertransmitters under the Wireless Power Consortium's Qi™ standard may belimited to operability at a maximum coil-to-coil separation gap (whichmay be referred to herein as a “separation gap” or “gap”) of about 3millimeters (mm) to about 5 mm. The separation gap is sometimes known asthe Z-height or Z-distance and is generally measured as the distancebetween the transmitter coil and receiver coil.

As the adoption of wireless power grows, commercial applications arerequiring a power transmitter capable of transferring power to a powerreceiver with a gap greater than 3-5 mm. By way of example, cabinetsand/or counter tops may be more than 3-5mm thick and as a result,prevent wireless charging through such furniture. As another example,modern mobile devices may be used with cases, grip devices, and/orwallets, among other things, that can obstruct wireless powertransmission to the mobile device and/or create a separation gap thatdisallows operability of wireless power transmission. Legacy wirelesspower transmitter designs further may be incapable of desired commercialapplications (e.g., through object chargers, under table chargers,infrastructure chargers, ruggedized computing device charging, amongother things), due to the limitations in separation gap inherent tolegacy, near-field wireless power transfer systems. Increasing theseparation gap, while keeping satisfactory performance (e.g., thermalperformance, transfer/charging speed, efficiency, etc.) will increasethe number of commercial applications that can utilize wireless power.

SUMMARY

New wireless power transmitters and/or associated base stations aredesired that are capable of delivering wireless power signals to a powerreceiver at a separation gap larger than the about 3 mm to about 5 mmseparation gaps of legacy transmitters.

In an embodiment, the overall structure of the transmitter is configuredin a way that allows the transmitter to transfer power at an operatingfrequency of about 87 kilohertz (kHz) to about 360 kHz and achieve thesame and/or enhanced relative characteristics (e.g., rate of powertransfer, speed of power transfer, power level, power level management,among other things) of power transfer as legacy transmitters thatoperated in that frequency range. As a result, the separation gap may beincreased from about 3-5mm to around 15mm or greater using the overallstructure of the transmitter. In an embodiment, a transmitter may beconfigured with a ferrite core that substantially surrounds thetransmitter antenna on three sides. The only place that the ferrite coredoes not surround the transmitter antenna is on the top (e.g., in thedirection of power transfer) and where the power lines connect to thetransmitter antenna. This overall structure of the transmitter allowsfor the combination of power transfer characteristics, power levelcharacteristics, self-resonant frequency restraints, designrequirements, adherence to standards bodies' required characteristics,bill of materials (BOM) and/or form factor constraints, among otherthings, that allow for power transfer over larger separation gaps.

Transmission of one or more of electrical energy, electrical power,electromagnetic energy or electronic data signals from one of suchcoiled antennas to another, generally, operates at an operatingfrequency and/or an operating frequency range. The operating frequencymay be selected for a variety of reasons, such as, but not limited to,power transfer characteristics, power level characteristics,self-resonant frequency restraints, design requirements, adherence tostandards bodies' required characteristics, bill of materials (BOM)and/or form factor constraints, among other things. It is to be notedthat, “self-resonating frequency,” as known to those having skill in theart, generally refers to the resonant frequency of an inductor due tothe parasitic characteristics of the component.

In accordance with one aspect of the disclosure, a power transmitter forwireless power transfer at an operating frequency selected from a rangeof about 87 kilohertz (kHz) to about 360 kHz is disclosed. The powertransmitter includes a control and communications unit and an invertercircuit configured to receive input power and convert the input power toa power signal. The power transmitter further includes a coil configuredto transmit the power signal to a power receiver, the coil formed ofwound Litz wire and including a first coil portion and a second coilportion, the first coil portion defining a top face and a firstdiameter, the second coil portion defining a second diameter, the seconddiameter being greater than the first diameter. The power transmitterfurther includes a shielding comprising a ferrite core and defining acavity and a magnetic ring, the cavity configured such that the ferritecore substantially surrounds all but the top face of the first coilportion and the second coil portion is positioned, at least in part,above the magnetic ring.

In a refinement, a shielding outer edge of the shielding extends about4.5 millimeters (mm) to about 6.5 mm outward from a coil outer edge ofthe coil.

In a refinement, the first coil portion and the second coil portion aresubstantially concentric, with respect to one another.

In a refinement, the first diameter is a first outer diameter in a rangeof about 40 mm to about 50 mm.

In a further refinement, the second diameter is a second inner diameterin a range of about 45 mm to about 65 mm.

In a refinement, one or both of the first coil portion and the secondcoil portion have a thickness in a range of about 2 mm to about 3 mm.

In a refinement, the first coil portion includes a plurality of coillayers, including, at least, a first layer and a second layer.

In a further refinement, the first layer includes a first number ofturns in a range of about 4 turns to about 5 turns, and wherein thesecond layer includes a second number of turns in a range of about 4turns to about 5 turns.

In a refinement, the second coil portion includes a plurality of coillayers including, at least, a first layer and a second layer.

In a further refinement, the first layer includes a first number ofturns in a range of about 1 turn to about 3.5 turns, and wherein thesecond layer includes a second number of turns in a range of about 1turn to about 3.5 turns.

In a refinement, the Litz wire is a bifilar Litz wire.

In another refinement, the Litz wire has a diameter in a range of about1 mm to about 1.5 mm and includes a plurality of strands, the pluralityof strands including a number of strands in a range of about 80 strandsto about 120 strands.

In a further refinement, each of the plurality of strands has a diameterin a range of about 0.05 mm to about 0.1 mm.

In accordance with another aspect of the disclosure, a base station forwireless power transfer at an operating frequency selected from a rangeof about 87 kilohertz (kHz) to about 360 kHz is disclosed. The basestation includes an interface surface, a control and communications unitand an inverter circuit configured to receive input power and convertthe input power to a power signal. The base station further includes acoil configured to transmit the power signal to a power receiver, thecoil formed of wound Litz wire and including a first coil portion and asecond coil portion, the first coil portion defining a top face and afirst diameter, the second coil portion defining a second diameter, thesecond diameter being greater than the first diameter. The base stationfurther includes a shielding comprising a ferrite core and defining acavity and a magnetic ring, the cavity configured such that the ferritecore substantially surrounds all but the top face of the first coilportion and the second coil portion is positioned, at least in part,above the magnetic ring.

In a refinement, the interface surface is separated from the first coilportion to define an interface gap that is defined by an interface gapdistance, the interface gap distance in a range of about 8 millimeters(mm) to about 10 mm.

In a refinement, the second coil portion is positioned within theinterface gap distance.

In a refinement, the interface surface extends across substantially allof the top face of the first coil portion and a top face of the secondcoil portion.

In a refinement, the base station further includes at least one userfeedback mechanism configured for aiding a user in aligning a powerreceiver with an active area for wireless power transmission via thecoil, the power receiver configured to acquire near field inductivepower from the coil.

In a further refinement, the at least one user feedback mechanismincludes a marking on the interface surface to indicate the location ofthe active area.

In another further refinement, the at least one user feedback mechanismincludes a visual feedback display, this is configured to indicateproper alignment of the power receiver with the active area.

In another further refinement, the at least one user feedback mechanismincludes one or more of an audible feedback mechanism, a tactilefeedback mechanism that is configured to indicated if the power receiveris in proper alignment with the active area or a tactile feedbackmechanism that is configured to indicate if the power receiver is inproper alignment with the active area.

These and other aspects and features of the present disclosure will bebetter understood when read in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exemplary block diagram of an embodiment of a wirelesspower transfer system, in accordance with an embodiment of the presentdisclosure.

FIG. 2 is an exemplary block diagram for a power transmitter, which maybe used in conjunction with the wireless power transfer system of FIG.1, in accordance with FIG. 1 and an embodiment of the presentdisclosure.

FIG. 3 is an exemplary block diagram for components of a control andcommunications system of the power transmitter of FIG. 2, in accordancewith FIGS. 1-2 and an embodiment of the present disclosure.

FIG. 4 is an exemplary block diagram for components of a sensing systemof the control and communications system of FIG. 3, in accordance withFIGS. 1-3 and an embodiment of the present disclosure.

FIG. 5 is an exemplary block diagram for components of a powerconditioning system of the power transmitter of FIGS. 1-2, in accordancewith FIGS. 1-2 and an embodiment of the present disclosure.

FIG. 6 is an exemplary electrical schematic diagram of components of thepower transmitter of FIGS. 1-5, in accordance with FIGS. 1-5 and thepresent disclosure.

FIG. 7 is a perspective view of a shape of a transmitter coil of thepower transmitter of FIGS. 1-6, in accordance with FIGS. 1-6 and anembodiment of the present disclosure.

FIG. 8 is a cross-section of components of a base station, with whichthe power transmitter 20 is associated, in accordance with FIGS. 1-7 andthe present disclosure.

FIG. 9 is a perspective view of a shielding associated with thetransmitter coil of FIGS. 1-8, in accordance with FIGS. 1-8 and anembodiment of the present disclosure.

FIG. 10A is a perspective view of the transmitter coil of FIGS. 1-8 andthe shielding of FIGS. 8 and 9, in accordance with FIGS. 1-9 and thepresent disclosure.

FIG. 10B is an exploded perspective view of the transmitter coil ofFIGS. 1-8 and the shielding of FIGS. 8 and 9, in accordance with FIGS.1-9 and the present disclosure.

FIG. 11A is an exemplary block diagram for an embodiment of the basestation of FIGS. 1-10 in accordance with FIGS. 1-10 and the presentdisclosure.

FIG. 11B is an exemplary block diagram for another embodiment of thebase station of FIGS. 1-10 in accordance with FIGS. 1-10 and the presentdisclosure.

FIG. 12 is a flow chart for an exemplary method for designing a powertransmitter, in accordance with FIGS. 1-11 and the present disclosure.

FIG. 13 is a flow chart for an exemplary method for manufacturing apower transmitter, in accordance with FIGS. 1-11 and the presentdisclosure.

While the following detailed description will be given with respect tocertain illustrative embodiments, it should be understood that thedrawings are not necessarily to scale and the disclosed embodiments aresometimes illustrated diagrammatically and in partial views. Inaddition, in certain instances, details which are not necessary for anunderstanding of the disclosed subject matter or which render otherdetails too difficult to perceive may have been omitted. It shouldtherefore be understood that this disclosure is not limited to theparticular embodiments disclosed and illustrated herein, but rather to afair reading of the entire disclosure and claims, as well as anyequivalents thereto. Additional, different, or fewer components andmethods may be included in the systems and methods.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth byway of examples in order to provide a thorough understanding of therelevant teachings. However, it should be apparent to those skilled inthe art that the present teachings may be practiced without suchdetails. In other instances, well known methods, procedures, components,and/or circuitry have been described at a relatively high-level, withoutdetail, in order to avoid unnecessarily obscuring aspects of the presentteachings.

Referring now to the drawings and with specific reference to FIG. 1, awireless power transfer system 10 is illustrated. The wireless powertransfer system 10 provides for the wireless transmission of electricalsignals, such as, but not limited to, electrical energy, electricalpower signals, and electromagnetic energy. Additionally, the wirelesspower transfer system 10 may provide for wireless transmission ofelectronically transmittable data (“electronic data”) independent ofand/or associated with the aforementioned electrical signals.Specifically, the wireless power transfer system 10 provides for thewireless transmission of electrical signals via near field magneticcoupling. As shown in the embodiment of FIG. 1, the wireless powertransfer system 10 includes a power transmitter 20 and a power receiver30. The power receiver 30 is configured to receive electrical energy,electrical power, electromagnetic energy, and/or electronic data from,at least, the power transmitter 20.

As illustrated, the power transmitter 20 and power receiver 30 may beconfigured to transmit electrical energy, via transmitter coil 21 andreceiver coil 31, electrical power, electromagnetic energy, and/orelectronically transmittable data across, at least, a separationdistance or gap 17. A separation distance or gap, such as the gap 17, inthe context of a wireless power transfer system, such as the system 10,does not include a physical connection, such as a wired connection.There may be intermediary objects located in a separation distance orgap, such as the gap 17, such as, but not limited to, air, a countertop, a casing for an electronic device, a grip device for a mobiledevice, a plastic filament, an insulator, a mechanical wall, among otherthings; however, there is no physical, electrical connection at such aseparation distance or gap.

The combination of the power transmitter 20 and the power receiver 30create an electrical connection without the need for a physicalconnection. “Electrical connection,” as defined herein, refers to anyfacilitation of a transfer of an electrical current, voltage, and/orpower from a first location, device, component, and/or source to asecond location, device, component, and/or destination. An “electricalconnection” may be a physical connection, such as, but not limited to, awire, a trace, a via, among other physical electrical connections,connecting a first location, device, component, and/or source to asecond location, device, component, and/or destination. Additionally oralternatively, an “electrical connection” may be a wireless electricalconnection, such as, but not limited to, magnetic, electromagnetic,resonant, and/or inductive field, among other wireless electricalconnections, connecting a first location, device, component, and/orsource to a second location, device, component, and/or destination.

Alternatively, the gap 17 may be referenced as a “Z-Distance,” because,if one considers an antenna 21, 31 to be disposed substantially along acommon X-Y plane, then the distance separating the antennas 21, 31 isthe gap in a “Z” or “depth” direction. However, flexible and/ornon-planar coils are certainly contemplated by embodiments of thepresent disclosure and, thus, it is contemplated that the gap 17 may notbe uniform, across an envelope of connection distances between theantennas 21, 31. It is contemplated that various tunings,configurations, and/or other parameters may alter the possible maximumdistance of the gap 17, such that electrical transmission from the powertransmitter 20 to the power receiver 30 remains possible.

The wireless power transfer system 10 operates when the powertransmitter 20 and the power receiver 30 are coupled. As defined herein,the terms “couples,” “coupled,” and “coupling” generally refers tomagnetic field coupling, which occurs when the energy of a transmitterand/or any components thereof and the energy of a receiver and/or anycomponents thereof are coupled to each other through a magnetic field.Coupling of the power transmitter 20 and the power receiver 30, in thesystem 10, may be represented by a resonant coupling coefficient of thesystem 10 and, for the purposes of wireless power transfer, the couplingcoefficient for the system 10 may be in the range of about 0.01 and 0.9.

The power transmitter 20 may be operatively associated with a basestation 11. The base station 11 may be a device, such as a charger, thatis able to provide near-field inductive power, via the power transmitter20, to a power receiver. In some examples, the base station 11 may beconfigured to provide such near-field inductive power as specified inthe Qi™ Wireless Power Transfer System, Power Class 0 Specification. Insome such examples, the base station 11 may carry a logo to visuallyindicate to a user that the base station 11 complies with the Qi™Wireless Power Transfer System, Power Class 0 Specification.

The power transmitter 20 may receive power from an input power source12. The base station 11 may be any electrically operated device, circuitboard, electronic assembly, dedicated charging device, or any othercontemplated electronic device. Example base stations 11, with which thepower transmitter 20 may be associated therewith, include, but are notlimited to including, a device that includes an integrated circuit,cases for wearable electronic devices, receptacles for electronicdevices, a portable computing device, clothing configured withelectronics, storage medium for electronic devices, charging apparatusfor one or multiple electronic devices, dedicated electrical chargingdevices, activity or sport related equipment, goods, and/or datacollection devices, among other contemplated electronic devices.

The input power source 12 may be or may include one or more electricalstorage devices, such as an electrochemical cell, a battery pack, and/ora capacitor, among other storage devices. Additionally or alternatively,the input power source 12 may be any electrical input source (e.g., anyalternating current (AC) or direct current (DC) delivery port) and mayinclude connection apparatus from said electrical input source to thewireless transmission system 20 (e.g., transformers, regulators,conductive conduits, traces, wires, or equipment, goods, computer,camera, mobile phone, and/or other electrical device connection portsand/or adaptors, such as but not limited to USB or lighting ports and/oradaptors, among other contemplated electrical components).

Electrical energy received by the power transmitter 20 is then used forat least two purposes: providing electrical power to internal componentsof the power transmitter 20 and providing electrical power to thetransmitter coil 21. The transmitter coil 21 is configured to wirelesslytransmit the electrical signals conditioned and modified for wirelesstransmission by the power transmitter 20 via near-field magneticcoupling (NFMC). Near-field magnetic coupling enables the transfer ofelectrical energy, electrical power, electromagnetic energy, and/orelectronically transmissible data wirelessly through magnetic inductionbetween the transmitter coil 21 and a receiving coil 31 of, orassociated with, the power receiver 30. Near-field magnetic coupling mayenable “inductive coupling,” which, as defined herein, is a wirelesspower transmission technique that utilizes an alternatingelectromagnetic field to transfer electrical energy between two or moreantennas/coils. Such inductive coupling is the near field wirelesstransmission of electrical energy between two magnetically coupled coilsthat are tuned to resonate at a similar frequency. Further, suchnear-field magnetic coupling may provide connection via “mutualinductance,” which, as defined herein is the production of anelectromotive force in a circuit by a change in current in at least onecircuit magnetically coupled to the first.

In one or more embodiments, the inductor coils of either the transmittercoil 21 or the receiver coil 31 are strategically positioned tofacilitate reception and/or transmission of wirelessly transferredelectrical energy, power, electromagnetic energy and/or data throughnear field magnetic induction. Antenna operating frequencies maycomprise all operating frequency ranges, examples of which may include,but are not limited to, about 87 kHz to about 360 kHz (Qi™ interfacestandard). The operating frequencies of the coils 21, 31 may beoperating frequencies designated by the International TelecommunicationsUnion (ITU) in the Industrial, Scientific, and Medical (ISM) frequencybands.

As known to those skilled in the art, a “resonant frequency” or“resonant frequency band” refers to a frequency or frequencies whereinamplitude response of the antenna is at a relative maximum, or,additionally or alternatively, the frequency or frequency band where thecapacitive reactance has a magnitude substantially similar to themagnitude of the inductive reactance. In one or more embodiments thetransmitting antenna resonant frequency band extends from about 87 kHzto about 360 kHz. In one or more embodiments the inductor coil of thereceiver coil 31 is configured to resonate at a receiving antennaresonant frequency or within a receiving antenna resonant frequencyband.

In some examples, the transmitting coil and the receiving coil of thepresent disclosure may be configured to transmit and/or receiveelectrical power at a baseline power profile having a magnitude up toabout 5 watts (W). In some other examples, the transmitting coil and thereceiving coil of the present disclosure may be configured to transmitand/or receive electrical power at an extended power profile, supportingtransfer of up to 15 W of power.

The power receiver 30 is configured to acquire near-field inductivepower from the power transmitter 20. In some examples, the powerreceiver 30 is a subsystem of an electronic device 14. The electronicdevice 14 may be any device that is able to consume near field inductivepower as specified in the Qi™ Wireless Power Transfer System, PowerClass 0 Specification. In some such examples, the electronic device 14may carry a logo to visually indicate to a user that the electronicdevice 14 complies with the Specification.

The electronic device 14 may be any device that requires electricalpower for any function and/or for power storage (e.g., via a batteryand/or capacitor). Additionally or alternatively, the electronic device14 may be any device capable of receipt of electronically transmissibledata. For example, the device may be, but is not limited to being, ahandheld computing device, a mobile device, a portable appliance, anintegrated circuit, an identifiable tag, a kitchen utility device, anautomotive device, an electronic tool, an electric vehicle, a gameconsole, a robotic device, a wearable electronic device (e.g., anelectronic watch, electronically modified glasses, altered-reality (AR)glasses, virtual reality (VR) glasses, among other things), a portablescanning device, a portable identifying device, a sporting good, anembedded sensor, an Internet of Things (IoT) sensor, IoT enabledclothing, IoT enabled recreational equipment, industrial equipment,medical equipment, a medical device, a tablet computing device, aportable control device, a remote controller for an electronic device, agaming controller, among other things.

For the purposes of illustrating the features and characteristics of thedisclosed embodiments, arrow-ended lines are utilized to illustratetransferrable and/or communicative signals and various patterns are usedto illustrate electrical signals that are intended for powertransmission and electrical signals that are intended for thetransmission of data and/or control instructions. Solid lines indicatesignal transmission of electrical energy, electrical power signals,and/or electromagnetic energy over a physical and/or wireless electricalconnection, in the form of power signals that are, ultimately, utilizedin wireless power transmission from the power transmitter 20 to thepower receiver 30. Further, dotted lines are utilized to illustrateelectronically transmittable data signals, which ultimately may bewirelessly transmitted from the power transmitter 20 to the powerreceiver 30.

Turning now to FIG. 2, the wireless power transfer system 10 isillustrated as a block diagram including example sub-systems of thepower transmitter 20. The wireless transmission system 20 may include,at least, a power conditioning system 40, a control and communicationssystem 26, a sensing system 50, and the transmission coil 21. A firstportion of the electrical energy input from the input power source 12 isconfigured to electrically power components of the wireless transmissionsystem 20 such as, but not limited to, the control and communicationssystem 26. A second portion of the electrical energy input from theinput power source 12 is conditioned and/or modified for wireless powertransmission, to the power receiver 30, via the transmission coil 21.Accordingly, the second portion of the input energy is modified and/orconditioned by the power conditioning system 40. While not illustrated,it is certainly contemplated that one or both of the first and secondportions of the input electrical energy may be modified, conditioned,altered, and/or otherwise changed prior to receipt by the powerconditioning system 40 and/or transmission control system 26, by furthercontemplated subsystems (e.g., a voltage regulator, a current regulator,switching systems, fault systems, safety regulators, among otherthings).

The control and communications system 26, generally, comprises digitallogic portions of the power transmitter 20. The control andcommunications system 26 receives and decodes messages from the powerreceiver 30, executes the relevant power control algorithms andprotocols, and drives the frequency of the AC waveform to control thepower transfer. As discussed in greater detail below, the control andcommunications system 26 also interfaces with other subsystems of thepower transmitter 20. For example, the control and communications system26 may interface with other elements of the power transmitter 20 foruser interface purposes.

Referring now to FIG. 3, with continued reference to FIGS. 1 and 2,subcomponents and/or systems of the control and communications system 26are illustrated. The control and communications system 26 may include atransmission controller 28, a communications system 29, a driver 48, anda memory 27.

The transmission controller 28 may be any electronic controller orcomputing system that includes, at least, a processor which performsoperations, executes control algorithms, stores data, retrieves data,gathers data, controls and/or provides communication with othercomponents and/or subsystems associated with the power transmitter 20,and/or performs any other computing or controlling task desired. Thetransmission controller 28 may be a single controller or may includemore than one controller disposed to control various functions and/orfeatures of the power transmitter 20. Functionality of the transmissioncontroller 28 may be implemented in hardware and/or software and mayrely on one or more data maps relating to the operation of the powertransmitter 20. To that end, the transmission controller 28 may beoperatively associated with the memory 27. The memory may include one ormore of internal memory, external memory, and/or remote memory (e.g., adatabase and/or server operatively connected to the transmissioncontroller 28 via a network, such as, but not limited to, the Internet).The internal memory and/or external memory may include, but are notlimited to including, one or more of a read only memory (ROM), includingprogrammable read-only memory (PROM), erasable programmable read-onlymemory (EPROM or sometimes but rarely labelled EROM), electricallyerasable programmable read-only memory (EEPROM), random access memory(RAM), including dynamic RAM (DRAM), static RAM (SRAM), synchronousdynamic RAM (SDRAM), single data rate synchronous dynamic RAM (SDRSDRAM), double data rate synchronous dynamic RAM (DDR SDRAM, DDR2, DDR3,DDR4), and graphics double data rate synchronous dynamic RAM (GDDRSDRAM, GDDR2, GDDR3, GDDR4, GDDR5, a flash memory, a portable memory,and the like. Such memory media are examples of nontransitory machinereadable and/or computer readable memory media.

While particular elements of the control and communications system 26are illustrated as independent components and/or circuits (e.g., thedriver 48, the memory 27, the communications system 29, among othercontemplated elements) of the control and communications system 26, suchcomponents may be integrated with the transmission controller 28. Insome examples, the transmission controller 28 may be an integratedcircuit configured to include functional elements of one or both of thetransmission controller 28 and the power transmitter 20, generally.

As illustrated, the transmission controller 28 is in operativeassociation, for the purposes of data transmission, receipt, and/orcommunication, with, at least, the memory 27, the communications system29, the power conditioning system 40, the driver 48, and the sensingsystem 50. The driver 48 may be implemented to control, at least inpart, the operation of the power conditioning system 40. In someexamples, the driver 48 may receive instructions from the transmissioncontroller 28 to generate and/or output a generated pulse widthmodulation (PWM) signal to the power conditioning system 40. In somesuch examples, the PWM signal may be configured to drive the powerconditioning system 40 to output electrical power as an alternatingcurrent signal, having an operating frequency defined by the PWM signal.

The sensing system 50 may include one or more sensors, wherein eachsensor may be operatively associated with one or more components of thepower transmitter 20 and configured to provide information and/or data.The term “sensor” is used in its broadest interpretation to define oneor more components operatively associated with the power transmitter 20that operate to sense functions, conditions, electrical characteristics,operations, and/or operating characteristics of one or more of the powertransmitter 20, the power receiver 30, the input power source 12, thebase station 11, the transmission coil 21, the receiver coil 31, alongwith any other components and/or subcomponents thereof.

As illustrated in the embodiment of FIG. 4, the sensing system 50 mayinclude, but is not limited to including, a thermal sensing system 52,an object sensing system 54, a receiver sensing system 56, electricalsensor(s) 57 and/or any other sensor(s) 58. Within these systems, theremay exist even more specific optional additional or alternative sensingsystems addressing particular sensing aspects required by anapplication, such as, but not limited to: a condition-based maintenancesensing system, a performance optimization sensing system, astate-of-charge sensing system, a temperature management sensing system,a component heating sensing system, an IoT sensing system, an energyand/or power management sensing system, an impact detection sensingsystem, an electrical status sensing system, a speed detection sensingsystem, a device health sensing system, among others. The object sensingsystem 54, may be a foreign object detection (FOD) system.

Each of the thermal sensing system 52, the object sensing system 54, thereceiver sensing system 56 and/or the other sensor(s) 58, including theoptional additional or alternative systems, are operatively and/orcommunicatively connected to the transmission controller 28. The thermalsensing system 52 is configured to monitor ambient and/or componenttemperatures within the power transmitter 20 or other elements nearbythe power transmitter 20. The thermal sensing system 52 may beconfigured to detect a temperature within the power transmitter 20 and,if the detected temperature exceeds a threshold temperature, thetransmission controller 28 prevents the power transmitter 20 fromoperating. Such a threshold temperature may be configured for safetyconsiderations, operational considerations, efficiency considerations,and/or any combinations thereof. In a non-limiting example, if, viainput from the thermal sensing system 52, the transmission controller 28determines that the temperature within the power transmitter 20 hasincreased from an acceptable operating temperature to an undesiredoperating temperature (e.g., in a non-limiting example, the internaltemperature increasing from about 20° Celsius (C) to about 50° C., thetransmission controller 28 prevents the operation of the powertransmitter 20 and/or reduces levels of power output from the powertransmitter 20. In some non-limiting examples, the thermal sensingsystem 52 may include one or more of a thermocouple, a thermistor, anegative temperature coefficient (NTC) resistor, a resistancetemperature detector (RTD), and/or any combinations thereof.

As depicted in FIG. 4, the transmission sensing system 50 may includethe object sensing system 54. The object sensing system 54 may beconfigured to detect presence of unwanted objects in contact with orproximate to the power transmitter 20. In some examples, the objectsensing system 54 is configured to detect the presence of an undesiredobject. In some such examples, if the transmission controller 28, viainformation provided by the object sensing system 54, detects thepresence of an undesired object, then the transmission controller 28prevents or otherwise modifies operation of the power transmitter 20. Insome examples, the object sensing system 54 utilizes an impedance changedetection scheme, in which the transmission controller 28 analyzes achange in electrical impedance observed by the transmission coil 21against a known, acceptable electrical impedance value or range ofelectrical impedance values. Additionally or alternatively, in someexamples the object sensing system 54 may determine if a foreign objectis present by measuring power output associated with the powertransmitter 20 and determining power input associated with a receiverassociated with the power transmitter 20. In such examples, the objectsensing system 54 may calculate a difference between the powerassociated with the power transmitter 20 and the power associated withthe receiver and determine if the difference indicates a loss,consistent with a foreign object not designated for wireless powertransmission.

Additionally or alternatively, the object sensing system 54 may utilizea quality factor (Q) change detection scheme, in which the transmissioncontroller 28 analyzes a change from a known quality factor value orrange of quality factor values of the object being detected, such as thereceiver coil 31. The “quality factor” or “Q” of an inductor can bedefined as (frequency (Hz)xinductance (H))/resistance (ohms), wherefrequency is the operational frequency of the circuit, inductance is theinductance output of the inductor and resistance is the combination ofthe radiative and reactive resistances that are internal to theinductor. “Quality factor,” as defined herein, is generally accepted asan index (figure of measure) that measures the efficiency of anapparatus like an antenna, a circuit, or a resonator. In some examples,the object sensing system 54 may include one or more of an opticalsensor, an electro-optical sensor, a Hall effect sensor, a proximitysensor, and/or any combinations thereof.

The receiver sensing system 56 is any sensor, circuit, and/orcombinations thereof configured to detect presence of any wirelessreceiving system that may be couplable with the power transmitter 20. Insome examples, if the presence of any such wireless receiving system isdetected, wireless transmission of electrical energy, electrical power,electromagnetic energy, and/or data by the power transmitter to saidwireless receiving system is enabled. In some examples, if the presenceof a wireless receiver system is not detected, wireless transmission ofelectrical energy, electrical power, electromagnetic energy, and/or datais prevented from occurring. Accordingly, the receiver sensing system 56may include one or more sensors and/or may be operatively associatedwith one or more sensors that are configured to analyze electricalcharacteristics within an environment of or proximate to the powertransmitter 20 and, based on the electrical characteristics, determinepresence of a power receiver 30.

The electrical sensor(s) 57 may include any sensors configured fordetecting and/or measuring any current, voltage, and/or power within thepower transmitter 20. Information provided by the electrical sensor(s)57, to the transmission controller 28, may be utilized independentlyand/or in conjunction with any information provided to the transmissioncontroller 28 by one or more of the thermal sensing system 52, theobject sensing system 54, the receiver sensing system 56, the othersensor(s) 58, and any combinations thereof.

Referring now to FIG. 5, and with continued reference to FIGS. 1-4, ablock diagram illustrating an embodiment of the power conditioningsystem 40 is illustrated. At the power conditioning system 40,electrical power is received, generally, as a DC power source, via theinput power source 12 itself or an intervening power converter,converting an AC source to a DC source (not shown). A voltage regulator46 receives the electrical power from the input power source 12 and isconfigured to provide electrical power for transmission by the coil 21and provide electrical power for powering components of the powertransmitter 20. Accordingly, the voltage regulator 46 is configured toconvert the received electrical power into at least two electrical powersignals, each at a proper voltage for operation of the respectivedownstream components: a first electrical power signal to electricallypower any components of the power transmitter 20 and a second portionconditioned and modified for wireless transmission to the wirelessreceiver system 30. As illustrated in FIG. 3, such a first portion istransmitted to, at least, the sensing system 50, the transmissioncontroller 28, and the communications system 29; however, the firstportion is not limited to transmission to just these components and canbe transmitted to any electrical components of the power transmitter 20.

The second portion of the electrical power is provided to an amplifier42 of the power conditioning system 40, which is configured to conditionthe electrical power for wireless transmission by the coil 21. Theamplifier may function as an inverter, which receives an input DC powersignal from the voltage regulator 46 and generates an AC as output,based, at least in part, on PWM input from the transmission controlsystem 26. The amplifier 42 may be or include, for example, a powerstage inverter. The use of the amplifier 42 within the powerconditioning system 40 and, in turn, the power transmitter 20 enableswireless transmission of electrical signals having much greateramplitudes than if transmitted without such an amplifier. For example,the addition of the amplifier 42 may enable the wireless transmissionsystem 20 to transmit electrical energy as an electrical power signalhaving electrical power from about 10 milliwatts (mW) to about 60 W.

FIG. 6 is an exemplary schematic diagram 120 for an embodiment of thepower transmitter 20. In the schematic, the amplifier 42 is afull-bridge inverter 142 which drives the transmitter coil 21 and aseries capacitor C_(S). In some examples, wherein the operatingfrequency of the power transmitter 20 is in the range of about 87 kHzand about 360 kHz, the transmitter coil 21 has a self-inductance in arange of about 5 μH to about 7 μH. In some such examples, C_(S) has acapacitance in a range of about 400 nF to about 450 nF.

Based on controls configured by the control and communications system26, an input power source 112, embodying the input power source 12, isaltered to control the amount of power transferred to the power receiver30. The input voltage of the input power source 112 to the full-bridgeinverter 142 may be altered within a range of about 1 volt (V) to about19 V, to control power output. In such examples, the resolution of thevoltage of the input power source 112 may be 10 millivolts (mV) or less.In some examples, when the power transmitter 20, 120 first applies apower signal for transfer to the power receiver 30, the power signal ofthe input power source 112 has an initial input power voltage in a rangeof about 4.5 V to about 5.5 V.

The transmitter coil 21 may be of a wire-wound type, wound of, forexample, Litz wire. As defined herein, Litz wire refers to a type ofmultistrand wire or cable utilized in electronics to carry analternating current at a frequency. Litz wire is designed to reduce skineffect and proximity effect losses in conductors at frequencies up toabout 1 MHz and consists of many thin wire strands, individuallyinsulated and twisted or woven together, following a pattern. In someexamples, the Litz wire may be no. 17 American Wire Gauge (AWG) (1.15mm) type 2 Litz wire, having 105 strands of no. 40 AWG (0.08 mmdiameter), or equivalent wire. In some examples, the Litz wire used forthe transmitter coil 21 may be a bifilar Litz wire. To that end,utilizing thicker Litz wire, such as the no. 17 AWG type 2 Litz wire,utilizing bifilar Litz wire, and combinations thereof, may result in anincreased Quality Factor (Q) for the transmitter coil 21 and higher Qmay be directly related to increases in gap 17 height and/or Z-Distance.As Q is directly related to the magnitude of the magnetic field producedby the transmitter coil 21 and, thus, with a greater magnitude magneticfield produced, the field emanating from the transmission antenna 21 canreach greater Z-distances and/or charge volumes, in comparison to legacytransmission coils, having lower Q designs. While Litz wire is describedand illustrated, other equivalents and/or functionally similar wires maybe used. Furthermore, other sizes and thicknesses of Litz wire may beused.

Turning to FIGS. 7A and 7B, exemplary diagrams 160 and 165,respectfully, are illustrated to portray dimensions of first and secondcoil portions 23, 25 of the transmitter coil 21. The diagrams 160, 165are top perspective views of the first and second coil portions 23, 25and show top faces 60, 65, respectively, of the first and second coilportions 23, 25 of the transmitter coil 21. Note that the diagrams 121,125 are not necessarily to scale and are for illustrative purposes. Thetop faces 60, 65 and the first and second coil portions 23, 25,generally, are relatively circular in shape.

As illustrated in FIG. 7A, a first outer diameter d_(o1) is defined asan exterior diameter of the first coil portion 23. In some examples, thefirst outer diameter d_(o1) has an outer diameter length in a range ofabout 40 mm to about 50 mm. A first inner diameter dpi is defined as thediameter of the void space in the interior of the first coil portion 23.The inner diameter dpi may have an inner diameter length in a range ofabout 15 mm to about 25 mm. The outer diameter d_(o1) and the innerdiameter d_(i1) may be relatively concentric, with respect to oneanother. The first coil portion 23 has a first thickness t_(w1), whichis defined as the thickness of the wire of a coil. The first thicknesst_(w1) may be in a range of about 2 mm to about 3 mm. In such examples,the first coil portion 23 may be made of Litz wire and include at leasttwo layers, the at least two layers stacked upon each other. Utilizationof one or more of an increased first inner diameter d_(i1), an increasedfirst outer diameter d_(o1), multiple Litz wire layers for the firstcoil portion 23, specific dimensions disclosed herein, and/orcombinations thereof, may be beneficial in achieving greater gap 17heights and/or Z-distances.

FIG. 7B similarly illustrated dimensions of the second coil portion 25,which has a second outer diameter d_(o2), defined as an exteriordiameter of the second coil portion 25. In some examples, the secondouter diameter d_(o2) has an outer diameter length in a range of about45 mm to about 60 mm. A second inner diameter d_(i2) is defined as thediameter of the space in the interior of the second coil portion 25. Thesecond inner diameter d_(i2) may have an inner diameter length in arange of about 40 mm to about 55 mm. The second outer diameter d_(o2)and the second inner diameter d_(i2) may be relatively concentric, withrespect to one another. The second coil portion 25 has a secondthickness t_(w2), which is defined as the thickness of the wire of acoil. The second thickness t_(w2) may be in a range of about 2 mm toabout 3 mm. In such examples, the second coil portion 25 may be made ofLitz wire and include at least two layers, the at least two layersstacked upon each other. Utilization of one or more of an increasedsecond inner diameter d_(i2), an increased second outer diameter d_(o2),multiple Litz wire layers for the second coil portion 25, specificdimensions disclosed herein, and/or combinations thereof, may bebeneficial in achieving greater gap 17 heights and/or Z-distances.

In some examples, the second inner diameter d_(i2) may be greater thanboth the first inner diameter d_(i1) and the first outer diameterd_(o1). In such examples, each of the first diameter d_(i1), secondinner diameter d_(i2), first outer diameter d_(o1), and second outerdiameter d_(o2) may be substantially concentric, with respect to oneanother. The first diameter d_(i1), second inner diameter d_(i2), firstouter diameter d_(o1), and second outer diameter d_(o2) all may beconfigured such that the outer first outer diameter d_(o1) is capable offitting within the area within the second inner diameter d_(i2).Additionally or alternatively, in some examples the first and secondthicknesses t_(w1), t_(w2) may be substantially similar; however, thefirst and second thicknesses t_(w1), t_(w2) need not be substantiallysimilar and may be configured differently.

Other shapes and sizes of the first coil portion 23 and second coilportion 25 may be selected based on the configuration with the selectionof the shape and size of the shielding of the transmitter coil. In theevent that a desired shielding is required, the transmitter coil 21 maybe shaped and sized such that the shielding surrounds the first coilportion 23 and the second coil portion 25 is positioned above saidshielding, in accordance with an embodiment.

Turning now to FIG. 8, a cross-sectional view of the transmitter coil21, within the base station 11, is illustrated. The first coil portion23 of the transmitter coil 21 is partially surrounded by a shielding 80of the transmitter coil 21 and the second coil portion 25 resides aboveor atop the shielding 80, as illustrated. The shielding 80 comprises aferrite core and defines a cavity 82, the cavity configured such thatthe ferrite core substantially surrounds all but the top face 60 of thefirst coil portion 23 when the first coil portion 23 is placed in thecavity. As used herein, “surrounds” is intended to include covers,encircles, enclose, extend around, or otherwise provide a shielding for.“Substantially surrounds,” in this context, may take into account smallsections of the coil that are not covered. For example, power lines mayconnect the transmitter coil 21 to a power source. The power lines maycome in via an opening in the side wall of the shielding 80. The firstcoil portion 23 at or near this connection may not be covered. Inanother example, the first coil portion 23 may rise slightly out of thecavity and thus the top section of the side walls may not be covered. Byway of example, substantially surrounds would include coverage of atleast 50+% of that section of the transmitter antenna. However, in otherexamples, the shielding may provide a greater or lesser extent ofcoverage for one or more sides of the first coil portion 23.

In an embodiment, as shown in FIG. 8, the shielding 80 surrounds atleast the entire bottom section of the first coil portion 23 and almostall of the side sections of the first coil portion 23. As used herein,the entire bottom section of the first coil portion 23 may include, forexample, the entire surface area of the first coil portion 23 or all ofthe turns of the Litz wire of the first coil portion 23.

In another embodiment, the shielding 80 may surround less than theentire bottom section of the first coil portion 23. For example,connecting wires (e.g., connecting wires 292, as best illustrated inFIGS. 10A, 10B and discussed below) may be run through an opening in thebottom of the shielding 80.

In an embodiment, as shown in FIG. 8, the shielding 80 is an “E-Core”type shielding, wherein a cavity 82 and structural elements of theshielding 80 are configured in an E-shape configuration, when theshielding is viewed, cross-sectionally, in a side view. The E-Coreconfiguration is further illustrated in FIG. 9, which is a perspectiveview of the shielding 80. The shielding 80 may include a magnetic core86, a magnetic backing 85, and a magnetic ring 84. The magnetic core 86is spaced inwardly from the outer edge of the magnetic backing 85 andprojects in an upward direction from the top surface of the magneticbacking 85. The magnetic core 86 and the magnetic ring 84 function tosurround the first coil portion 23 and to direct and focus magneticfields, hence improving coupling with the receiver coil 31 of the powerreceiver 30.

In addition to covering the entire outer diameter of the first coilportion 23, the shielding 80 may also cover the first inner diameter dpiof the first coil portion 23. That is, as shown, the inner section ofthe E-Core configuration may protrude upward through the middle of thefirst coil portion 23.

In an embodiment, the cavity 82 is configured such that the shielding 80covers the entire bottom section of the first coil portion and theentire side sections of the first coil portion 23. The top sectionproximate to the top face 60 of the first coil portion 23 is notcovered. The bottom section of the first coil portion is the side of thefirst coil portion 23 that is opposite of the direction of the primarypower transfer to the receiver coil. With a wire wound first coilportion 23, the side section of the first coil portion 23 includes theside section of the outer most winding of the first coil portion 23

As illustrated, the second coil portion 25 resides above or on top ofthe magnetic ring 84 of the shielding 80 and concentrically outward ofthe first coil portion 23. The magnetic ring 84 of the shielding maycover a bottom portion of the second coil portion 23. In some examples,positioning of the second coil portion 25 may be, at least in part,above the first coil portion 84. In other words, if one considers themagnetic backing 85 a proximal end of the base station 11 and aninterface surface 70 is a forward end within the base station 11, thesecond coil portion 25 may be positioned, at least in part, forward ofthe first coil portion 23, with the interface surface 70 forward of thesecond coil portion 23. The second portion 25 may be included tosupplement the magnetic field generated by the first coil portion 23, byitself, to improve spatial freedom for wireless power transfer betweenthe power transmitter 20 and a power receiver 30.

FIG. 10A is a perspective view of the transmitter coil 21 and theembodiment of the E-core shielding of FIG. 9 and FIG. 10B is an explodedperspective view of the transmitter coil 21 and the embodiment of theE-core shielding of FIG. 9. The transmitter coil 21 is positioned abovethe shielding 80, The combination of structural bodies of the shielding80, as discussed above, may include the combination of the magnetic core86, the magnetic backing 85, and magnetic ring 84. This magneticshielding combination functions to help direct and concentrate magneticfields created by transmitter coil 21 and can also limit side effectsthat would otherwise be caused by magnetic flux passing through nearbymetal objects. In some examples, the magnetic ring defines an opening88, in which a connecting wire 292 of the transmitter coil 21 can exitthe shielding 80.

As defined herein, a “shielding material,” from which the shielding 80is formed, is a material that captures a magnetic field. An example ofwhich is a ferrite material. The ferrite shield material selected forthe shielding 80 also depends on the operating frequency, as the complexmagnetic permeability (μ=μ′−j*μ″) is frequency dependent. The materialmay be a sintered flexible ferrite sheet or a rigid shield and becomposed of varying material compositions. In some examples, the ferritematerial for the shielding 80 may include a Ni—Zn ferrite, a Mn—Znferrite, and any combinations thereof.

Returning now to FIG. 8 and with continued reference to FIGS. 9 and 10,the shielding 80 is aligned with the transmitter coil 21 such that theshielding 80 substantially surrounds the first coil portion 23 on allsides, aside from the top face 60, and the second coil portion 25resides above the magnetic ring 84. In other words, the first coilportion 23 may be wound around the magnetic core 86 and be surrounded,on the bottom and sides, respectively, by the magnetic backing 85 andthe magnetic ring 84. As illustrated, the shielding 80, in the form ofone or both of the magnetic backing and the magnetic core, may extendbeyond the first outer diameter d_(o1) of the first coil portion 23 by ashielding extending distance d_(e). In some examples, the shieldingextending distance d_(e) may be in a range of about 5 mm to about 6 mm.The shielding 80, at the magnetic backing 85, and the first coil portion23 are separated from one another by a separation distance d_(s), asillustrated. In some examples, the separation distance d_(s) may be in arange of about 0.1 mm and 0.5 mm.

The interface surface 70 of the base station 11 is located at ainterface gap distance dint from the first coil portion 23 and theshielding 80. In some examples, the second coil portion 25 may reside,at least in part, within a gap between the shielding 80 and theinterface surface 11, defined by an interface gap distance d_(int). Theinterface surface 70 is a surface on the base station 11 that isconfigured such that when a power receiver 30 is proximate to theinterface surface 70, the power receiver 30 is capable of coupling withthe power transmitter 20, via near-field magnetic induction between thetransmitter coil 21 and the receiver coil 31, for the purposes ofwireless power transfer. In some examples, the interface gap distancedint may be in a range of about 8 mm to about 10 mm. In such examples,the d_(int) is greater than the standard required Z-distance for Qi™certified wireless power transmission (3-5 mm). Accordingly, by having agreater d_(int), empty space and/or an insulator can be positionedbetween the transmission coil 21 and the interface surface 70 tomitigate heat transfer to the interface surface 70, the power receiver30, and/or the electronic device 14 during operation. Further, such agreater d_(int) allows for interface design structures in which objectson or attached to the electronic device 14 may remain attached to theelectronic device during operation. As described in greater detailbelow, design features of the interface surface 70 may be included forinteraction with such objects for aligning the power transmitter 20 andthe power receiver 30 for operation.

Returning now to FIG. 10B, an exemplary coil 221 for use as thetransmitter coil 21 is illustrated in the exploded view of thetransmitter coil 21 and shielding 80. The coil 221 includes one or morefirst bifilar Litz wires 290 for a first bifilar coil layer 261 and asecond bifilar coil layer 262 of the first coil portion 23 and one ormore second bifilar Litz wires 295 for a first bifilar coil layer 296and a second bifilar coil layer 297 of the second coil portion 25.“Bifilar,” as defined herein, refers to a wire having two closelyspaced, parallel threads and/or wires. Each of the bifilar coil layers261, 262, 296, 297 include N number of turns. In some examples, each ofthe first and second bifilar coil layers 261, 262 of the first coilportion 23 include about 4.5 turns and/or the bifilar coil layers 261,262 may include a number of turns in a range of about 4 to about 5. Insome examples, each of the first and second bifilar coil layers 296, 297of the second coil portion 25 include about 2 turns and/or the bifilarcoil layers 261, 262 may include a number of turns in a range of about 1to about 3.5. In some examples, the one or more bifilar Litz wire 290,295 may be no. 17 AWG (1.15 mm) type 2 Litz wire, having 105 strands ofno. 40 AWG (0.08 mm diameter), or equivalent wire. Utilization ofmultiple layers, thick Litz wire, bifilar Litz wire, and anycombinations thereof, may result in the coil 21 achieving greater Qand/or may result in increases in gap 17 height and/or Z-distancebetween the coil 21 and a receiver coil.

While each of the first coil portion 23 and the second coil portion 25are illustrated in FIGS. 10A and 10B as having independent connectingwires, 292A, 292B, respectively, the first and second coil portions 23,25 need not have independent connecting wires 292 and may shareconnecting wires. In such examples wherein the first and second coilportions 23, 25 include independent connecting wires 292A, 292B,respectively, such connecting wires may be connected to the electricalcomponents of the power transmitter 20 (e.g., the power conditioningsystem 40, the control and communications system 26, any tuning elementsof the transmitter coil 21, any components thereof, or combinationsthereof), either in series or in parallel with respect to the electricalcomponents.

In examples wherein the first and second coil portions 23, 25 shareconnecting wires, a turn of the first coil portion 23 may combine, as aunitary body or wire, with a turn of the second coil portion 23, thuscreating a series connection between the first and second coil portions23, 25. For example, rather than end at a connecting wire 292, anoutermost turn of the first coil portion 23 may extend along and abovethe magnetic ring 84 to begin a first end of the innermost turn of thesecond coil portion 25. Alternatively, ends of the first and second coilportions 23, 25 may end at a unitary connecting wire 292 for connectionto the electrical components of the power transmitter 20 and, thus, bein parallel electrical connection, with respect to the electricalcomponents and/or electrical output of said components.

FIG. 11A is a first block diagram 311A for an implementation of the basestation 11. As illustrated, the power transmitter 20 is contained withinthe base station 11. In some examples, the base station 11 includes oneor more user feedback mechanisms 300, wherein each of the one or moreuser feedback mechanisms 300 are configured for aiding a user inaligning a power receiver 30 and/or its associated electronic device 14with an active area 310 for wireless power transmission via thetransmitter coil 21, wherein the power receiver 30 is configured toacquire near field inductive power from the transmitter coil 21. The“active area” 310, as defined herein, refers to any area, volume, and/orspace proximate to the interface surface 70 wherein the powertransmitter 20 is capable of transmitting near field inductive power toa power receiver 30.

The one or more user feedback mechanisms 300 may include one or more ofa visual feedback display 302, a tactile feedback mechanism 304, anaudible feedback mechanism 306, a marking 308 on the interface surface70, any other feedback mechanisms 300, and any combinations thereof. Thevisual feedback display 302 is configured for visually indicating properalignment of the power receiver 30 with the active area 310. The visualfeedback display 302 may include, but is not limited to including, avisual screen, a light, a light emitting diode (LED), a liquid crystaldisplay (LCD) display, other visual displays, and/or any combinationsthereof. The tactile feedback mechanism 304 is configured for tactilelyindicating if the power receiver 30 is in proper alignment with theactive area 310. The tactile feedback mechanism 304 may include, but isnot limited to including, a haptic feedback device, a vibrating device,other tactile feedback mechanisms, and any combinations thereof. Theaudible feedback device 306 is configured for audibly indicating if thepower receiver 30 is in proper alignment with the active area 310. Theaudio feedback mechanism 306 may include, but is not limited toincluding, a speaker, a sound generator, a voice generator, an audiocircuit, an amplifier, other audible feedback devices, and anycombinations thereof.

The marking 308 may be any visual and/or mechanical signifier,indicating where a user of the electronic device 14 should placehis/her/their electronic device 14 on the interface surface 70, suchthat the power transmitter 20 will be in proper alignment with the powerreceiver 30 of the electronic device 14. Additionally or alternatively,the marking 308 may indicate a location of the active area 310 and/or aproper location within the active area 70. In the exemplary embodimentof the diagram 311A, the marking 308A may be a substantiallytwo-dimensional visual indicator marked on the interface surface 70. Thesubstantially two-dimensional marking 308A may include, but is notlimited to including, a printed indicator, a logo, a message indicatinga user should place the electronic device 14 upon the marking 308A, anyother substantially two-dimensional markings, and any combinationsthereof.

In an alternative embodiment in a second schematic block diagram 311Billustrated in FIG. 11B, the marking 308B is a substantiallythree-dimensional and/or mechanical marking 308B, such as, but notlimited to, an indentation and/or notch in the interface surface 70. Thethree-dimensional marking 308B may be configured to interact withmechanical feature 72 of the electronic device 14. The mechanicalfeature 72 may be any mechanical feature of the electronic device 14and/or another connected mechanical feature and/or device associatedwith the electronic device 14. Accordingly, interaction between themechanical feature 72 and the three-dimensional marking 308B may beconfigured to align the power transmitter 20 with the power receiver 30of the electronic device 14. For example, the mechanical feature 72 maybe an external protrusion located relatively proximate to the powerreceiver 30 of electronic device 14 and the marking 308B is configuredto receive the mechanical feature and, by the nature of such receipt,the power transmitter 20 and the power receiver 30 are properly alignedfor near-field inductive wireless power transfer. In some such examples,the electronic device 14 is a mobile device, such as a smart phoneand/or tablet computing device, and the mechanical feature 72 may be anexternally attached grip device configured for gripping the electronicdevice 14 when in use. In such examples, the marking 308B is configuredto receive the grip device mechanical feature 72 and enable properalignment of the power transmitter 20 and the power receiver 30 fornear-field inductive wireless power transfer while the removablemechanical feature 72 remains attached to the electronic device 14.

Wireless power transmitters utilizing transmitter coils designed,manufactured, and/or implemented in accordance with the teachings of thepresent disclosure have shown, in experimental results to generate amagnetic field capable of capture by the receiver coil 30 at an extendedZ-distance of 8-15 mm. As discussed previously, Qi™ wireless transmittercoils typically operate between coil-to-coil distances of about 3 mm toabout 5 mm. The shaped-magnetics of the transmitter coil 21 have shownto favorably reshape a magnetic field so that coil-to-coil coupling canoccur at extended Z-distances, wherein the Z-distances are extendedabout 2 times to about 5 times the distance of standard Qi™ wirelesspower transmitters. Furthermore, the shaped-magnetics of the presentapplication can extend coupling of present day a Qi™ wireless powertransmitter at a Z-distance ranging about 5 mm to about 25 mm. Any ofthe E-core and/or additional or alternative custom shapes for theshielding 80, may successfully be used to reshape the magnetic field forextended Z-distance coupling by a minimum of a 5% compared to standardpresent-day power transmitters. In addition, any of the E-core andcustom shapes previously discussed, each in conjunction with itsrelation to a coil to the magnetic has also may further increasez-direction coupling by at least another 5%. An embodiment comprising astructure, the structure comprising a coil and a magnetic material,wherein a gap between the coil and the magnetic material residing at theinner diameter of the coil comprises 2 mm, reshapes the magnetic fieldso that coupling increases by 5%.

As is discussed above, the transmitter coils 21, power transmitters 20,and/or base stations 11, disclosed herein, may achieve greatadvancements in Z-distance and/or gap 17 height, when compared tolegacy, low-frequency (e.g., in a range of about 87 kHz to about 360kHz) transmission coils, power transmitters, and/or base stations. Tothat end, an extended Z-distance not only expands a linear distance,within which a receiver may be placed and properly coupled with atransmitter, but an extended Z-distance expands a three-dimensionalcharging and/or operational volume (“charge volume”), within which areceiver may receive wireless power signals from a transmitter. For thefollowing example, the discussion fixes lateral spatial freedom (X and Ydistances) for the receiver coil, positioned relative to the transmittercoil, as a control variable. Accordingly, for discussion purposes only,one assumes that the X and Y distances for the base stations 11, powertransmitters 20, and/or transmitter coils 21 are substantially similarto the X and Y distances for the legacy system(s). However, it iscertainly contemplated that the inventions disclosed herein may increaseone or both of the X-distance and Y-distance. Furthermore, while theinstant example uses the exemplary range of 8-10 mm for the Z-distanceof the base stations 11, power transmitters 20, and/or transmitter coils21, it is certainly contemplated and experimental results have shownthat the base stations 11, power transmitters 20, and/or transmittercoils 21 are certainly capable of achieving Z-distances having a greaterlength than about 10 mm, such as, but not limited to, up to 15 mm and/orup to 30 mm. Accordingly, the following table is merely exemplary andfor illustration that the expanded Z-distances, achieved by the basestations 11, power transmitters 20, and/or transmitter coils 21, havenoticeable, useful, and beneficial impact on a charge volume associatedwith one or more of the base stations 11, power transmitters 20, and/ortransmitter coils 21.

Spatial Freedom Comparison Charge Charge Z-dist Z-dist Vol. Vol. X-distY-dist (min) (max) (min) (max) Legacy 5 mm 5 mm  3 mm  5 mm  75 mm³ 125mm³ 11, 20, 21 5 mm 5 mm  8 mm 10 mm 200 mm³ 250 mm³ (8-10 mm. ver.) 11,20, 21 5 mm 5 mm 10 mm 15 mm 250 mm³ 375 mm³ (15 mm. ver.) 11, 20, 21 5mm 5 mm 15 mm 30 mm 375 mm³ 750 mm³ (30 mm. ver.)Thus, by utilizing the base stations 11, power transmitters 20, and/ortransmitter coils 21, the effective charge volume may increase by morethan 100 percent, when compared to legacy, low-frequency wireless powertransmitters. Accordingly, the base stations 11, power transmitters 20,and/or transmitter coils 21 may achieve large Z-distances, gap heights,and/or charge volumes that were not possible with legacy low frequency,but thought only possible in lower power, high frequency (e.g., aboveabout 2 Mhz) wireless power transfer systems.

FIG. 13 is an example block diagram for a method 1200 for designing thepower transmitter 20. The method 1200 includes designing and/orselecting the transmitter coil 21 for the power transmitter 20, asillustrated in block 1210. The method 1200 includes tuning the powertransmitter 20, as illustrated in block 1220. Such tuning may beutilized for, but not limited to being utilized for, impedance matching.

The method 1200 further includes designing the power conditioning system40 for the power transmitter 20, as illustrated in block 1230. The powerconditioning system 40 may be designed with any of a plurality of poweroutput characteristic considerations, such as, but not limited to, powertransfer efficiency, maximizing a transmission gap (e.g., the gap 17),increasing output voltage to a receiver, mitigating power losses duringwireless power transfer, increasing power output without degradingfidelity for data communications, optimizing power output for multiplecoils receiving power from a common circuit and/or amplifier, amongother contemplated power output characteristic considerations. Further,at block 1240, the method 1200 may determine and optimize a connection,and any associated connection components, to configure and/or optimize aconnection between the input power source 12 and the power conditioningsystem 40 of block 1230. Such determining, configuring, and/oroptimizing may include selecting and implementing protection mechanismsand/or apparatus, selecting and/or implementing voltage protectionmechanisms, among other things.

The method 1200 further includes designing and/or programing the controland communications system 26 of the power transmitter 20, as illustratedin block 1250. Components of such designs include, but are not limitedto including, the sensing system 50, the driver 41, the transmissioncontroller 28, the memory 27, the communications system 29, the thermalsensing system 52, the object sensing system 54, the receiver sensingsystem 56, the electrical sensor(s) 57, the other sensor(s) 58, in wholeor in part and, optionally, including any components thereof.

FIG. 14 is an example block diagram for a method 2200 for manufacturingthe power transmitter 20. The method 2200 includes manufacturing and/orselecting the transmitter coil 21 for the power transmitter 20, asillustrated in block 2210. The method 2200 includes tuning the powertransmitter 20, as illustrated in block 2220. Such tuning may beutilized for, but not limited to being utilized for, impedance matching.

The method 2200 further includes manufacturing the power conditioningsystem 40 for the power transmitter 20, as illustrated in block 2230.The power conditioning system 40 may be designed and/or manufacturedwith any of a plurality of power output characteristic considerations,such as, but not limited to, power transfer efficiency, maximizing atransmission gap (e.g., the gap 17), increasing output voltage to areceiver, mitigating power losses during wireless power transfer,increasing power output without degrading fidelity for datacommunications, optimizing power output for multiple coils receivingpower from a common circuit and/or amplifier, among other contemplatedpower output characteristic considerations. Further, at block 2240, themethod 2200 may include connecting and/or optimizing a connection, andany associated connection components, to configure and/or optimize aconnection between the input power source 12 and the power conditioningsystem 40 of block 2230. Such determining, manufacturing, configuring,and/or optimizing may include selecting and implementing protectionmechanisms and/or apparatus, selecting and/or implementing voltageprotection mechanisms, among other things.

The method 2200 further includes designing and/or programing the controland communications system 26 of the power transmitter 20, as illustratedin block 2250. Components of such designs include, but are not limitedto including, the sensing system 50, the driver 41, the transmissioncontroller 28, the memory 27, the communications system 29, the thermalsensing system 52, the object sensing system 54, the receiver sensingsystem 56, the electrical sensor(s) 57, the other sensor(s) 58, in wholeor in part and, optionally, including any components thereof.

As used herein, the phrase “at least one of” preceding a series ofitems, with the term “and” or “or” to separate any of the items,modifies the list as a whole, rather than each member of the list (i.e.,each item). The phrase “at least one of” does not require selection ofat least one of each item listed; rather, the phrase allows a meaningthat includes at least one of any one of the items, and/or at least oneof any combination of the items, and/or at least one of each of theitems. By way of example, the phrases “at least one of A, B, and C” or“at least one of A, B, or C” each refer to only A, only B, or only C;any combination of A, B, and C; and/or at least one of each of A, B, andC.

The predicate words “configured to”, “operable to”, and “programmed to”do not imply any particular tangible or intangible modification of asubject, but, rather, are intended to be used interchangeably. In one ormore embodiments, a processor configured to monitor and control anoperation or a component may also mean the processor being programmed tomonitor and control the operation or the processor being operable tomonitor and control the operation. Likewise, a processor configured toexecute code can be construed as a processor programmed to execute codeor operable to execute code.

A phrase such as “an aspect” does not imply that such aspect isessential to the subject technology or that such aspect applies to allconfigurations of the subject technology. A disclosure relating to anaspect may apply to all configurations, or one or more configurations.An aspect may provide one or more examples of the disclosure. A phrasesuch as an “aspect” may refer to one or more aspects and vice versa. Aphrase such as an “embodiment” does not imply that such embodiment isessential to the subject technology or that such embodiment applies toall configurations of the subject technology. A disclosure relating toan embodiment may apply to all embodiments, or one or more embodiments.An embodiment may provide one or more examples of the disclosure. Aphrase such an “embodiment” may refer to one or more embodiments andvice versa. A phrase such as a “configuration” does not imply that suchconfiguration is essential to the subject technology or that suchconfiguration applies to all configurations of the subject technology. Adisclosure relating to a configuration may apply to all configurations,or one or more configurations. A configuration may provide one or moreexamples of the disclosure. A phrase such as a “configuration” may referto one or more configurations and vice versa.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” or as an “example” is not necessarily to be construed aspreferred or advantageous over other embodiments. Furthermore, to theextent that the term “include,” “have,” or the like is used in thedescription or the claims, such term is intended to be inclusive in amanner similar to the term “comprise” as “comprise” is interpreted whenemployed as a transitional word in a claim. Furthermore, to the extentthat the term “include,” “have,” or the like is used in the descriptionor the claims, such term is intended to be inclusive in a manner similarto the term “comprise” as “comprise” is interpreted when employed as atransitional word in a claim.

All structural and functional equivalents to the elements of the variousaspects described throughout this disclosure that are known or latercome to be known to those of ordinary skill in the art are expresslyincorporated herein by reference and are intended to be encompassed bythe claims. Moreover, nothing disclosed herein is intended to bededicated to the public regardless of whether such disclosure isexplicitly recited in the claims. No claim element is to be construedunder the provisions of 35 U.S.C. § 112, sixth paragraph, unless theelement is expressly recited using the phrase “means for” or, in thecase of a method claim, the element is recited using the phrase “stepfor.”

Reference to an element in the singular is not intended to mean “one andonly one” unless specifically so stated, but rather “one or more.”Unless specifically stated otherwise, the term “some” refers to one ormore. Pronouns in the masculine (e.g., his) include the feminine andneuter gender (e.g., her and its) and vice versa. Headings andsubheadings, if any, are used for convenience only and do not limit thesubject disclosure.

While this specification contains many specifics, these should not beconstrued as limitations on the scope of what may be claimed, but ratheras descriptions of particular implementations of the subject matter.Certain features that are described in this specification in the contextof separate embodiments can also be implemented in combination in asingle embodiment. Conversely, various features that are described inthe context of a single embodiment can also be implemented in multipleembodiments separately or in any suitable sub-combination. Moreover,although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to a subcombination or variation of a sub combination.

1. A power transmitter for wireless power transfer at an operatingfrequency selected from a range of about 87 kilohertz (kHz) to about 360kHz, the power transmitter comprising: a control and communicationsunit; an inverter circuit configured to receive input power and convertthe input power to a power signal; a coil configured to transmit thepower signal to a power receiver, the coil formed of wound Litz wire andincluding a first coil portion and a second coil portion, the first coilportion comprising an inner edge and an outer edge; and a shieldingcomprising a ferrite core, a magnetic backing, and a magnetic ring,wherein the ferrite core, magnetic backing, and magnetic ring define acavity that is below a top face of the magnetic ring, wherein the firstcoil portion is positioned within the cavity such that the inner edge ofthe first coil portion surrounds the ferrite core and the outer edge ofthe first coil portion is substantially surrounded by the magnetic ring,wherein the second coil portion is positioned, at least in part, abovethe top face of the magnetic ring.
 2. The power transmitter of claim 1,wherein a shielding outer edge of the shielding extends about 4.5millimeters (mm) to about 6.5 mm outward from the outer edge of thefirst coil portion.
 3. The power transmitter of claim 1, wherein thefirst coil portion and the second coil portion are substantiallyconcentric, with respect to one another.
 4. The power transmitter ofclaim 1, wherein the outer edge of the first coil portion has a diameterin a range of about 40 mm to about 50 mm.
 5. The power transmitter ofclaim 4, wherein an inner edge of the second coil portion has a diameterin a range of about 45 mm to about 65 mm.
 6. The power transmitter ofclaim 1, wherein one or both of the first coil portion and the secondcoil portion have a thickness in a range of about 2 mm to about 3 mm. 7.The power transmitter of claim 1, wherein the first coil portionincludes a plurality of coil layers, including, at least, a first layerand a second layer.
 8. The power transmitter of claim 7, wherein thefirst layer includes a first number of turns in a range of about 4 turnsto about 5 turns, and wherein the second layer includes a second numberof turns in a range of about 4 turns to about 5 turns.
 9. The powertransmitter of claim 1, wherein the second coil portion includes aplurality of coil layers including, at least, a first layer and a secondlayer.
 10. The power transmitter of claim 9, wherein the first layerincludes a first number of turns in a range of about 1 turn to about 3.5turns, and wherein the second layer includes a second number of turns ina range of about 1 turn to about 3.5 turns.
 11. The power transmitter ofclaim 1, wherein the Litz wire is a bifilar Litz wire.
 12. The powertransmitter of claim 1, wherein the Litz wire has a diameter in a rangeof about 1 mm to about 1.5 mm and includes a plurality of strands, theplurality of strands including a number of strands in a range of about80 strands to about 120 strands.
 13. The power transmitter of claim 12,wherein each of the plurality of strands has a diameter in a range ofabout 0.05 mm to about 0.1 mm.
 14. A base station for a wireless powertransfer system at an operating frequency selected from a range of about87 kilohertz (kHz) to about 360 kHz, the base system comprising: aninterface surface; a control and communications unit; an invertercircuit configured to receive input power and convert the input power toa power signal; a coil configured to transmit the power signal to apower receiver, the coil formed of wound Litz wire and including a firstcoil portion and a second coil portion, the first coil portioncomprising an inner edge and an outer edge; and a shielding comprising aferrite core, a magnetic backing, and a magnetic ring, wherein theferrite core, magnetic backing, and magnetic ring define a cavity thatis below a top face of the magnetic ring, wherein the first coil portionis positioned within the cavity such that the inner edge of the firstcoil portion surrounds the ferrite core and the outer edge of the firstcoil portion is substantially surrounded by the magnetic ring, whereinthe second coil portion is positioned, at least in part, above the topface of the magnetic ring.
 15. The base station of claim 14, wherein theinterface surface is separated from the first coil portion to define aninterface gap that is defined by an interface gap distance, theinterface gap distance in a range of about 8 millimeters (mm) to about10 mm.
 16. The base station of claim 15, wherein the second coil portionis positioned within the interface gap distance.
 17. The base station ofclaim 14, wherein the interface surface extends across substantially allof a top face of the first coil portion and a top face of the secondcoil portion.
 18. The base station of claim 14, further comprising atleast one user feedback mechanism configured for aiding a user inaligning the power receiver with an active area for wireless powertransmission via the coil, the power receiver configured to acquire nearfield inductive power from the coil.
 19. The base station of claim 18,wherein the at least one user feedback mechanism includes a marking onthe interface surface to indicate the location of the active area. 20.The base station of claim 18, wherein the at least one user feedbackmechanism includes a visual feedback display that is configured toindicate proper alignment of the power receiver with the active area.